#include <algorithm>

#define DBG fprintf(stderr,"%d: %d\n",ts::myRank,__LINE__)

struct Expr;

typedef ts::TVar<Expr> TExpr;

struct Expr : private ts::TExtData
{
	private:

	TExpr* terms;

	public:

	Expr () : terms(0) {};

	void init (size_t s) {
		assert(!terms);
		terms = new TExpr[s];
		extDataSize() = s * sizeof(TExpr);
	};

	operator const TExpr* () const { return terms ? terms : (TExpr*)extData(); }
	operator       TExpr* ()       { return terms ? terms : (TExpr*)extData(); }

	Expr (const Expr& e) : terms(0) {
		TExpr* p = *this;
		const TExpr* q = e;
		for (unsigned i = 0; i < e.getLength(); i++)
			new (p++) TExpr(*q++);
	}

	size_t getLength () const {
		return extDataSize() / sizeof(TExpr);
	}

	TExpr& operator[] (int i) {
		return ((TExpr *)*this)[i];
	}

	~Expr () {
		if (terms)
			delete[] terms;
		else {
			TExpr* p = *this;
			for (unsigned i = 0; i < getLength(); i++)
				p++->~TExpr();
		}
	}
};

tfun int depth (TExpr e) {
	Expr& x = (Expr&) e;
	if (x.getLength() != 2)
		return 1;
	tval int x0 = depth(x[0]);
	tval int x1 = depth(x[1]);
	return std::max((int)x0, (int)x1) + 1;
}

tfun int main(int argc, char *argv[]) {
	TExpr e;
	((Expr&)e).init(0);
	for (int i = 0; i < (argc > 1 ? atoi(argv[1]) : 10); i++) {
		TExpr z;
		Expr& x = (Expr&) z;
		x.init(2);
		x[0] = e;
		x[1] = e;
		e = z;
	}
	printf("%d\n", (int)depth(e));
	return 0;
}